It is desirable to use vibrational analysis in order to monitor the health of components in vehicles and power plants that use rotating machineries, such as alternators and generators. Vibrational analysis generally requires a tachometer signal as a basis for rotational analysis. However, instrumenting a device with revolution counters, such as tachometers, may be relatively expensive and add additional costs for recertification of the device. Furthermore, mounting a tachometer on a device can also be cumbersome, inconvenient, or impossible.
A voltage waveform from three-phase rotating machinery, such as a motor or alternator, can be used as a tachometer signal if the voltage waveform is relatively clean. However, over time, as the three-phase rotating machinery degrades, the voltage waveform becomes increasingly noisy, inhibiting an ability to derive accurate timing information. Vibrational analysis using vibration signal processing functions requires a signal with accurate timing information.
Noise in a waveform may result in, for example, threshold level crossing glitches, short pulses, multiple threshold crossings, or the like.